Production of liquid hydrocarbons of low boiling point from olefines



Oct. 25, 1932- H AL 1,884,093

PRODUCTION OF LIQUID HYDROCARBONS OF LOW BOILING POINT FROM OLIEFINES Filed Feb. 17. 1927 amina g 4 I Z a: 5 '1 4L I H q I T vmn. I

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JZZvinmiEZasch waZZYFrankenz7ur3r .F r'ilzll inkler INVENTORS ATTORNEY S Patented Oct. 25, 1932 PATENT OFFICE ALWIN MITTASCH, OF MANNHEDI, WALTER FRANKENBURGEB AND FRITZ WINKLEB,

F LUDWIGSHAFEN-oN TflE-RflINE, GERMANY, .ASSIGNORS TO I. G. FARBENINDUS- TRIE AKTIENGESELLSCHAFT, 0F FRANKFORT-ONEHE-MAIN, GERMANY, A CGRPO RATION OF GERMANY PRODUCTION or LIQUID maoomnoivs' or Low BOILING romr FROM. 01mm Application filed February 17, 1927, Serial No. 169,128, and in Germany February 20, 1928.

This invention relates to the production of liquid hydrocarbons of low boiling point (including those of the aromatic series) from olefines, or gases containing the same, with the assistance of catalysts and with or Without the aid of pressure.

It is know that gaseous olefines can be converted into liquid hydrocarbons by exposin them to elevated temperatures and, if desire to elevated pressures. This method of working, however, is in no way satisfactory, as the speed of the reactionand the yield of liquid products are comparatively small; further, a considerable portion of the olefines is converted into methane and carbon and is thereby lost for the desired purpose.

We have now discovered a number of catalysts, with the aid of which the said difiiculties can be overcome to a large extent. The first group of catalysts suitable for the said reaction consists of the a noble metals and copper. It is advisable that these metals should not be employed in a state of more or less fine division, but preferably in such a form as to exhibit more or less large coherent surfaces. For example, copper turnings, copper wire gauze, silver turnings, gold and the like may be advantageously so used; a copper tube, for example, also exerts the desired catalytic action. Other valuable catalysts are compounds and particularly oxygen compounds of the alkali metals. Compounds of potassium, rubidium and cesium are particularly active for this purpose, but compounds of sodium andof lithium may also be used with advantage. Mixed catalysts containing salts or oxids of other metals in addition to the said alkali compounds are preferably employed. The salts of the oxygen acids of phosphorus, and also those of boron and antimony, are particularly effective not only when they contain the alkali metals but also when they contain other metals as the basic constituent. Even the acids themselves, or their anhydrids on carriers, act in a similar manner, as do also the reduction products of the-salts, which may be formed spontaneouslyin many cases in practice by the action of reducing gases. For example, calcium phosphate, zinc antimonate or copper borate, and the like, or also mixturas of these or simila compounds, may be use The production of liquid hydrocarbons of low boiling point from the olefines may be efiected under any suitable pressure. The

temperature to be employed depends on the composition of the gases, on the nature of the catalyst and on the pressure. As a rule, the operation may be carried out at a temperature up to 900 C. when the amount of olefines in the gases is small, and up to 800 C. when the content is higher and when employing elevated pressure. The most suitable temperafrom 300 to 400 (1., the products usually contain large amounts of liquid olefines and the amount of naphthenes and benzol hydrocarbons is usually very small. It increases considerably, however, with a rise of temperature, and, at about 550 C. only small quantities of unsaturated compounds are still present, the bulk of the products consisting of benzol hydrocarbons and naphthenes in varying proportions. The transformation of olefines or gases containing the saineinto liquid hydrocarbons of low boiling point proceeds with particular advantage if materials giving rise to the separation of carbon be excluded from the reaction. For this purpose the interior of the hot porticnsof the iron or steel apparatus employed may be lined for example with copper, silver, quartz, ferrosilicon another like materials.

Since more or less small quantities of methane may be formed as an undesirable product from the olefines during the process, it has been found advantageous to counteract this undesirable reaction by adding methane itself, or gases which furnish methane, such as the oxids of carbon together with hydrogen if necessary. The undecomposed residual gas may be passed, after the separation of cooler C the condensable hydrocarbons, through another pressure. apparatus, or returned to the cycle of operations in the same apparatus.

Under certain circumstances it is preferable to eliminate from the crude gases containin the olefines, such fractions as are especia y rich in polymerisable constituents, such as ethylene, propylene, acetylene, ethane,

ropane, and the like, by special treatment in any suitable manner, in particular by fractional liquefaction or by adsorption by means of active charcoal or silica, and then to subject these gas mixtures separately to the conversion into liquid hydrocarbons.

The hydrocarbons remaining in the gases after separation of the liquid products formed may also be recovered and treated for themselves as aforedescribed, instead of passing the residual gas directly through another or, in a circular course, through the same reaction apparatus.

When industrial gases containing sulfur are used, the elimination of the sulfur is particularly beneficial.

The ollowing examples will further illustrate how the said invention may be carried into practical eflect, reference being had to the accompanying diagrammatic I drawing showing by way of example one type of ap- P paratus suitable for carrying out the invention, ,butthe invention is 'notlimitedto these examples.

v Emample 1 Brown-coal-tar oil supplied from the container A is heated to about 700 C. in a retort B. The disengaged gases are cooled in a- "and the liquid constituents namely water and oils separated in the vessel D. The gases are passed to a compressor E where they are compressed to about 50 atmospheres, and

are then led through a pressure tube which is,

lined with a copper tube F and heated from outside to 500 C. Abundant quantities of liquid hydrocarbons, consisting chiefly of benzol hydrocarbons, benzines and naphthenes, are separated by a cooler G and collected in .a vessel H under pressure whilst the residual gas is returned to the pressure tube by a circulation pump I. In order to prevent the gas in circulation from becoming too heavily charged with nonreactive constituents, a certain portion of it is drawn off. from time totime by a pipe'K, and suitably treated, for example with active charcoal in a container L in order to recover the valuable constituents still therein, such as olefines and the like for the purpose of returning them to the process. The nature and yield of the valuable liquid hydrocarbons produced depend primarily on the temperature employed.

Ewample 2 to a large extent vaporized, carried away by the steam is then passed through a 2-inch tube of ferrosilicon, heated to 950 C. 'n which the transformation into gaseous hydrocarbons takes place. The issuing mixture of gases and steam is cooled in order to condense the steam, its composition then being 4 per cent of carbon dioxid, 15 per cent of ethylene, 7 per cent of propylene and butylene, 7 per cent of carbon monoxid, 36.6 per cent of hydrogen, 9.6 per cent of methane and 20.8 per cent of nitrogen. This gas is next conducted at ordinary pressure, and at a temperature of about 850 C. over a catalyst'composed of pumice and potassium bichromate, which treatment results in the production of a liquid which boils below 80 C. and contains up to 90 per cent of benzene.

The brown-coal-tar may be replaced by other materials such as coal tar, low-temperature tar, and the like.

Example 3 A gas consisting of 3 per cent of carbon dioxid, 35 per cent of ethylene, propylene and butylene, 7 per cent 23 per cent of hydrogen, methane, and 12 per cent of nitrogen, is assed, at a temperature of 850 C. and at the rate of 10 to 13 litres an hour, through a co per tube with an internal diameter of 20 mil 1- metres, and containing if required a roll of copper wire auze .20 centimetres in length. One-third o the heavy hydrocarbons are transformed, in a single passage, into a liquid containing only 5 per cent of tar. After the tar has been removed, this liquid boils below 20 per cent of 150 (3., and consists of approximately 60 per cent of benzene and 40 per cent of benzine.

No carbonis deposited ,on the walls of the,

tube-or on the copper gauze.

An extensive transformation without deposition of carbon can also be obtainedby the use of silver and gold.

Example 4 treated, for example, purified or hydrogenated, before use, if necessary. Natural gases, low-temperature distillation gases, cracking-process gases, oil gases, coke-oven gases, and the like, and also gases containing ethylene, and the like, and produced by any of carbon monoxid,

- metresinlength. The gas issuing from the Example 5 An oil gas containing about 46 per cent of, "methane, 30 per cent of unsaturated hydrocarbons, per cent of hy rogen and 4 per 7 cent of carbon monoxid, together with small quantities of carbon dioxid, oxygen and nitrogemis passed,u nder ordinary pressure, at the rate of litres an hour. through a quartz tube, 1 metre in length and 3 centimetres internal diameter, the middle section of which,

for a length of centimetres, is filled with a mixture of calcium pyrophosphate and copper bronze,'this portion of the tube being surrounded by an electric furnacoSO centicontactchamber, which is heated tofrom '630 to 670 C. is passed through twocondensing vessels cooled with a mixture of ice and common'salt. and through 8 to 10 such vessels cooled with a mixture of-acetone and carbon dioxid. About 85 per cent of the unsaturated hydrocarbons contained .in-the original gas are transformed into a liquid product containing up to 'Z 0 per cent ofbenzene, together with naphthalene and tar. V V

A similar effect is obtained "with borates,

. such as copper borate, as alsowith ffreeacids or anhydrids, such'as boric acid or-phos-' phorus pentoxid, deposited on pumice. when these substances are used, the formation of soot which occurs when many other substances are "employed, especially the ma ority of metals. no longer apparent, but

only deposits of ioliaceous carbon with a 'inetalliclustre are formed.

What we claim is:

l. The process at producing liquid hydrocarlionsoflow boiling-point, which comprises heating gases comprising olexines at bet-ween about 200 and 900 C; and while excluding substantial amounts of free oxygen with a catalyst comprising at least one of the constituents from the group-consisting of noble metals and copper. said metals being em ployed in a form exhibiting coherent surfaces. 9,.- The process of producn g'liquid hydrocarbons of low boiling point. which comprises heating gases comprisingoleiines at between shout 200 and 800 Cl and while excludingsnhstantial amounts oi Tee oxygen with acatalyst comprising at least oneoi the constituents from the group consisting of noble metals and copper, said metals being employed in a form exhibiting coherent surfaces. 3. The process of producing liquid hydrocarbons of low boiling point, which comprises heating gases comprising-defines at between about 200 and 900 {1, under apressure in copper, said metals being employed in a, form exhibiting coherent surfaces.

4;. lihe process of producing liquid hydro-- carbons of low boiling p0int,which comprises heating gases comprising olefines in the pres-- the group consisting of noble metals and copper, the said metals being employed in a form.

exhibiting coherent surfaces.

5. The process of producing liquid hydrocarbons of low boiling point, which comprises heatin gases comprising olefines in the presence of compounds furnishing methane at between about 200 and 900 C. and while excluding substantial amounts of free oxygen with a catalyst comprising at least one of the constituents from the group consisting of noble metalsand copper, the said metals being employed in a form exhibiting coherent surfaces.

0. The process of producing liquid hydrocarbons of low boiling point, which comprises heating gasescomprising .olefines, while preventing the materials undergoing treatment from coming into contact with free iron while at'high temperatures,-at between about 200 and 900 C. and while-excluding substantial amounts of free oxygen with a catalyst comprising at least one ofthe constituents from the group consisting of noble metals and copper.

' ,7. Aprocess-for the productionof liquid hydrocarbons of low boiling point, which comprises passing gases containing olefines intofcontact with a coherent surface of copper,

at a temperature of about 500 C. under a pressure or" 50 atmospheres and while excluding substantial amounts of free oxygen;

in testimony whereof wehave hereunto set our hands.

ALWIN MITTASCH. WALTER FRANKENBURGER. FRITZ WINKLER.

excess of atmospheric pressure with a catalyst comprising. at least: one of the constituents from the group consisting of noble metals and 

